Are some minis multiquantal?

Matthew Frerking, Salvador Borges, Martin Wilson

Research output: Contribution to journalArticle

36 Scopus citations

Abstract

The amplitude distribution of miniature postsynaptic currents (minis) in many central neurons has a large variance and positive skew, but the sources of this variance and skew are unresolved. Recently it has been proposed that spontaneous Ca2+ influx into a presynaptic bouton with multiple release sites could cause spontaneous multiquantal minis by synchronizing release at all sites in the bouton, accounting for both the large variance and skew of the mini distribution. We tested this hypothesis by evoking minis with internally perfused, buffered Ca2+ and the secretagogue α-latrotoxin, both in the absence of external Ca2+. With these manipulations, the synchronized release model predicts that the mini distribution should collapse to a Gaussian distribution with a reduced coefficient of variation. Contrary to this expectation, we find that mini amplitude distributions under these conditions retain a large variance and positive skew and are indistinguishable from amplitude distributions of depolarization-evoked minis, strongly suggesting that minis are uniquantal.

Original languageEnglish (US)
Pages (from-to)1293-1304
Number of pages12
JournalJournal of neurophysiology
Volume78
Issue number3
DOIs
StatePublished - Sep 1997

ASJC Scopus subject areas

  • Neuroscience(all)
  • Physiology

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    Frerking, M., Borges, S., & Wilson, M. (1997). Are some minis multiquantal? Journal of neurophysiology, 78(3), 1293-1304. https://doi.org/10.1152/jn.1997.78.3.1293